/* bzflag
 * Copyright (c) 1993-2020 Tim Riker
 *
 * This package is free software;  you can redistribute it and/or
 * modify it under the terms of the license found in the file
 * named COPYING that should have accompanied this file.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef __COMMANDMANAGER_H__
#define __COMMANDMANAGER_H__

#include "common.h"

/* system interface headers */
#include <string>
#include <map>
#include <vector>

/* common interface headers */
#include "common.h"
#include "Singleton.h"


#define CMDMGR (CommandManager::instance())

class CommandManager : public Singleton<CommandManager>
{

public:

    CommandManager() = default;
    ~CommandManager() = default;

    // type of function that implements command.  function should return
    // a string with the output of the command (or the empty string if
    // there's no output).
    typedef std::vector<std::string> ArgList;
    typedef std::string (*CommandFunction)(const std::string& name, const ArgList&, bool* error);
    typedef void (*Callback)(const std::string& name, void* userData);

    // add/replace a command handler
    void              add(const std::string& name,
                          CommandFunction, const std::string& help);

    // remove a command handler
    void              remove(const std::string& name);

    // get the help string for a command
    std::string           getHelp(const std::string& name) const;

    // execute a command
    std::string           run(const std::string& name, const ArgList& args, bool *ret = NULL) const;

    // parse and execute a command
    std::string           run(const std::string& cmd, bool *ret = NULL) const;

    // invoke the callback for each registered command
    void              iterate(Callback, void* userData) const;

private:

    static const char*    readValue(const char* string, std::string* value);
    static const char*    readUnquoted(const char* string, std::string* value);
    static const char*    readQuoted(const char* string, std::string* value);
    static const char*    skipWhitespace(const char* string);

    struct CmdInfo
    {
    public:
        CommandFunction func;
        std::string     help;
    };
    typedef std::map<std::string, CmdInfo> Commands;

    Commands          commands;
};


#endif /* __COMMANDMANAGER_H__ */

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